Cyclobutanone, 2-hydroxy- synthesis

Cyclobutanediol, 1,2-dimethyl- synthesis, 53 Cyclobutanone, 2-hydroxy- synthesis, 54 Cyclobutanones synthesis, 77, 79, 335-336 Cyclobutene synthesis, 142... 

Tabic 5. Enantioselective Synthesis of 2-Alkyl- and 2-Aryl-2-(hydroxy-methyl)cyclobutanones by Asymmetric Epoxidation and 1,2-Rearrangement of Cyclopropylidene Alcohols55... 

Hsiao, C.-N. et al. Efficient Syntheses of Protected (2S,3S)-2,3-Bis(hydroxy-methyl)cyclobutanone, Key Intermediates for the Synthesis of Chiral Carbocyclic Analogues of Oxetanocin. 4.1 1990 [127]... 

It was actually in the course of a synthesis of Mori that the true absolute configuration of ( + )-lineatin (296) was definitely confirmed. This started with a [2 + 2] cycloaddition between isoprene and dichloroketene, giving a mixture of two isomeric dichlorocyclobutanones 333 and 334 (3.3 1). After reduction with zinc and acetic acid, the major cyclobutanone 335 was separated. Aldol condensation of the anion of 335 with acetone enabled the isopropyl side chain to be introduced. The later stages of the synthesis of ( )-lineatin are shown in Scheme 27, and the overall yield was 3.8%. In the course of diis synthesis, however, the alcohol 336 was resolved using the chiral hydroxy lactone 252, available fix>m commercial (lR,3/f)-c s-chrysanthemic acid. The ether 337 was shown by X-ray crystallography to have the absolute configuration demonstrated. Since it was related to natural (+)-lineatin, the absolute configuration of the latter was established. ... 

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