Dipolar addition to cyclic vinyl sulfones leading to dual conformation tricycles

• Steven S. Y. Wong,
• Michael G. Brant,
• Christopher Barr,
• Allen G. Oliver and
• Jeremy E. Wulff

Beilstein J. Org. Chem. 2013, 9, 1419–1425, doi:10.3762/bjoc.9.159

• synthesis of a family of [3.3.0] bicyclic vinyl sulfones starting from 3-sulfolene [30], and their elaboration to inhibitors of viral neuraminidase (Scheme 1) [31]. Understanding the conformational preferences of the underlying bicyclic structure was crucial to the design and assembly of such inhibitors. In

Synthesis of oxa-bridged derivatives from Diels–Alder bis-adducts of butadiene and 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene

• Faiz Ahmed Khan and
• Karuppasamy Parasuraman

Beilstein J. Org. Chem. 2010, 6, No. 64, doi:10.3762/bjoc.6.64

• Faiz Ahmed Khan Karuppasamy Parasuraman Department of Chemistry, Indian Institute of Technology, Kanpur-208 016, India 10.3762/bjoc.6.64 Abstract Bis-adducts of 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene and 1,3-butadiene, generated in situ from 3-sulfolene, have been synthesized in excellent

• derivatives; ruthenium; 3-sulfolene; Introduction 3-Sulfolene is a nonflammable, nontoxic, nonhygroscopic and stable crystalline solid and is a convenient equivalent for gaseous 1,3-butadiene [1][2][3] and is commonly used for in situ generation of 1,3-butadiene as the diene component in Diels–Alder

• )” [16]. In our reinvestigation we used 3-sulfolene as a 1,3-butadiene source to prepare both the mono- and bis-adducts. The two diastereomeric bis-adducts were separated and the relative stereochemistry was established by single crystal X-ray diffraction and 1H NMR spectroscopy. The bis-adducts were