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3 Polish Journal of Chemistry

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Diastereoselective Addition of Grignard Reagents to Chiral alfa-Ketoimides Derived from Oppolzer's Sultam

Raszplewicz K., Sikorska L., Kiegiel K., Bałakier T., Jurczak J.

Polish Journal of Chemistry

2005

Vol. 79 / nr 12

1901-1907

Additions of various Grignard reagents to N-pyruvoyl- (3) and N-phenylglyoxyloyl- (2R)-bornane-10,2-sultam (4) under thermal and Lewis-acid catalytic conditions are studied. High diastereoselectivity was observed in these reactions, and in the case of vinylmagnesium bromide additions to -ketoimide 4 a change of direction of asymmetric induction was found.

Homologation of Protected Monosaccharides at the Terminal Position with Grignard C1 Reagents

Zamojski A.

Polish Journal of Chemistry

2003

Vol. 77 / nr 3

257-281

The survey presents details of the recently introduced general method of homologation of monosaccharides. This method is based on chain-elongation of a protected monosaccharide from the terminal carbon atom. The terminal CH2OH group is oxidized to the aldehyde grouping and next reacted with an alkoxymethylmagnesium chloride (C1 Grignard) to form directly stereoisomeric homologues. The yields of the homologation products are high. Experiments aiming at improvement of the stereoselectivity of the reactions are described. The application of another C1 Grignard reagent, (phenyldimethylsilyl)methylmagnesium chloride, is presented. The advantages and disadvantages of the method are discussed. All syntheses connected with the important bacterial heptose, L-glycero-D-manno-heptose and its oligosaccharides are described.

Highly Diastereoselective Addition of Grignard Reagents to N-Glyoxyloyl-(2R0-bornane-10,2-sultam-Comparative Studies

Raszplewicz K., Sikorska L., Kiegiel K., Jurczak J.

Polish Journal of Chemistry

2002

Vol. 76 / nr 11

1595-1600

N-Glyoxyloyl-(2R)-bornane-10,2-sultam (3), readily prepared from (2R)-bornane-10,2- sultam (1), was used in the Grignard reaction with methylmagnesium bromide (4a), phenylmagnesium chloride (4b), benzylmagnesium chloride (4c), allylmagnesium chloride (4d), and vinylmagnesium bromide (4e). Reactions of 3 with Grignard reagents 4a-d led to the desired adducts 5 with predominance of the (14S)-diastereoisomer. The reaction of 3 with vinylmagnesium bromide (4e) failed to give the adduct of type 5. Stereochemical models for the reactions studied are proposed.