Phase- vanishing halolactonization of neat substrates

• Nicole Windmon and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2008, 4, No. 29, doi:10.3762/bjoc.4.29

• and structure determination [5][6]. Traditionally, a halolactonization is done in a mixture of aqueous solvent and an organic co-solvent in the presence of a base, such as sodium bicarbonate [7][8]. Reagents commonly used in halolactonization are I2/NaHCO3 [9], Br2 [10], IBr [11]and ICl [12]. We

Vinylogous Mukaiyama aldol reactions with 4-oxy-2-trimethylsilyloxypyrroles: relevance to castanospermine synthesis

• Roger Hunter,
• Sophie C. M. Rees-Jones and
• Hong Su

Beilstein J. Org. Chem. 2007, 3, No. 38, doi:10.1186/1860-5397-3-38

• adduct in 63% yield following conventional work-up and chromatography. Although an X-ray structure determination was not carried out, the tlc and spectral characteristics provided strong evidence that adduct 6e had the same C4/5 stereochemistry as 6a, b. For example, the coupling constant between H-5/H-6

A hydrogen- bonded channel structure formed by a complex of uracil and melamine

• Reji Thomas and
• G. U. Kulkarni

Beilstein J. Org. Chem. 2007, 3, No. 17, doi:10.1186/1860-5397-3-17

• (see Table 1 and Supporting Information File 1). The intermolecular interactions were analyzed using PLATON package [10] and are listed in Table 2. The crystal structure determination gave the asymmetric unit as shown in Figure 1a. The molecular complex crystallizes in C2/c space group with single

The oxanorbornene approach to 3-hydroxy, 3,4-dihydroxy and 3,4,5-trihydroxy derivatives of 2-aminocyclohexanecarboxylic acid

• Ishmael B. Masesane,
• Andrei S. Batsanov,
• Judith A. K. Howard,
• Raju Mondal and
• Patrick G. Steel

Beilstein J. Org. Chem. 2006, 2, No. 9, doi:10.1186/1860-5397-2-9

• reduction with Zn/HCl followed by addition of (Boc)2O and a large excess of iPr2NEt. At this stage, confirmation of the correct assignment of the relative stereochemistry for each isomer was realised by an X-ray crystallographic structure determination of the endo carbamate 2b (see Supporting Information