Bridgehead vicinal diallylation of norbornene derivatives and extension to propellane derivatives via ring-closing metathesis

• Sambasivarao Kotha and
• Rama Gunta

Beilstein J. Org. Chem. 2016, 12, 1877–1883, doi:10.3762/bjoc.12.177

• propellanes via ring-closing metathesis. Single-crystal X-ray diffraction analysis of four compounds led to the realization of configurational correction of earlier reported molecules. Keywords: norbornene; propellane derivatives; ring-closing metathesis; single-crystal X-ray diffraction; vicinal

• further converted into various other useful functionalities for further synthetic manipulation by adopting the appropriate functional group transformations. Strategy Our approach to various propellane derivatives is shown in Figure 1. The target propellane 1 could be assembled from diallyl compound 2 via

• values [41]. Conclusion This methodology was found to be useful to synthesize various propellane derivatives containing a norbornene moiety by employing RCM sequence. Moreover, we have firmly established the configuration of allyl groups at bridgehead position of norbornene derivatives by single-crystal

Design and synthesis of propellane derivatives and oxa-bowls via ring-rearrangement metathesis as a key step

• Sambasivarao Kotha and
• Rama Gunta

Beilstein J. Org. Chem. 2015, 11, 1727–1731, doi:10.3762/bjoc.11.188

• Sambasivarao Kotha Rama Gunta Department of Chemistry, Indian Institute of Technology-Bombay, Powai, Mumbai-400 076, India 10.3762/bjoc.11.188 Abstract Various intricate propellane derivatives and oxa-bowls have been synthesized via a ring-rearrangement metathesis (RRM) as a key step starting

• from readily accessible starting materials such as p-benzoquinone, 1,4-naphthoquinone and 1,4-anthraquinone. Keywords: allylation; propellane derivatives; quinones; ring-rearrangement metathesis; Introduction The synthesis of complex target structures requires bond-disconnection analysis of the

• ] we conceived a new and simple route to propellane derivatives and oxa-bowls [21][22][23][24][25][26]. This strategy starts from simple starting materials and involves a Diels–Alder (DA) reaction [27][28] and RRM as the key steps. Results and Discussion Strategy The retrosynthetic strategy to diverse

Hybrid macrocycle formation and spiro annulation on cis-syn-cis-tricyclo[6.3.0.0^2,6]undeca-3,11-dione and its congeners via ring-closing metathesis

• Sambasivarao Kotha,
• Ajay Kumar Chinnam and
• Rashid Ali

Beilstein J. Org. Chem. 2015, 11, 1123–1128, doi:10.3762/bjoc.11.126

• ]. Also, based on Fischer indolization and ring-closing metathesis (RCM), we have developed a new strategy to indole-based propellane derivatives [57]. Here, the tricyclic dione 2 required was prepared starting with the Cookson’s dione 4 in two steps involving flash vacuum pyrolysis (FVP) and

Synthesis of indole-based propellane derivatives via Weiss–Cook condensation, Fischer indole cyclization, and ring-closing metathesis as key steps

• Sambasivarao Kotha,
• Ajay Kumar Chinnam and
• Arti Tiwari

Beilstein J. Org. Chem. 2013, 9, 2709–2714, doi:10.3762/bjoc.9.307

• Sambasivarao Kotha Ajay Kumar Chinnam Arti Tiwari Department of Chemistry, Indian Institute of Technology-Bombay, Powai, India, Fax: 022-2572 7152 10.3762/bjoc.9.307 Abstract A variety of highly functionalized indole-based [n.3.3]propellane derivatives is described. The synthesis of the

• propellane derivatives involves a Weiss–Cook condensation, a Fischer indole cyclization, and a ring-closing metathesis as key steps. Keywords: allylation; indole derivatives; propellanes; ring-closing metathesis; Weiss–Cook condensation; Introduction Propellanes are tricyclic systems conjoined with carbon

• vincristine-resistant KB cancer cells [23][24]. Minfiensine alkaloid [25][26][27][28][29][30][31] containing a novel 1,2,3,4-tetrahydrocarbazole ring skeleton shows anticancer activity [32]. König and co-workers identified some propellane derivatives as cannabinoid CB1 receptor antagonists [33], which are