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Reaction of grignard reagents with a steroidal A-ring lactone and peracid oxidation of a resultant 6-phenyl-2,3-dihydropyran

✍ Scribed by Shangara S. Dehal; Brian A. Marples; Reginald J. Stretton

Publisher: Elsevier Science
Year: 1978
Tongue: French
Weight: 198 KB
Volume: 19
Category: Article
ISSN: 0040-4039
DOI: 10.1016/s0040-4039(01)86840-4

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✦ Synopsis

The reactions of Grignard reagents with lactones are commonplace. However, few examples of their reactions with saturated steroidal lactones are reported,1 although recent interest has been shown in their reactions with A-ring enol lactones. 2 The reaction of phenylmagnesium bromide with the g-lactone (1; R=CHOHCHs) is reported lb to give the anomalous product (2; R1=H. R2=CHOHCHs). We have found that the d-lactone (1; R=CaH17)3 reacts in a similar manner with phenylmagnesium bromide, giving the dihydropyran (2; R1=H, R2=CsH17) (50%) but somewhat different ly with pmethoxyphenyl magnesium bromide, giving the tetrahydropyran (3) (35%), the hydroxyolefin (4) (16%), and the dihydropyran (2; Rl=OMe, R2=CaH17) (8%).

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