Reactions with diazoalkanes homologation

Two types of products are generally obtained by reaction of ketones with diazoalkanes a homologous carbonyl compound and a small amount of oxirane. The reaction scheme is presented in Eq. 85. 

Addition of the diazoalkane nucleophile is followed by an reaction with ring-closure or a homologous ketone is formed with a 1,2-alkyl rearrangement (shift). Spirooxiranes are produced from cyclic ketone derivatives with diazomethane (Eq. 86). ... 

Homologation of carbonyl compounds. The very bulky organoaluminums promote reaction of aldehydes and ketones with diazoalkanes. Aldehydes afford ketones. 

The reaction of diazomethane derivatives with aldehydes and ketones, though a fairly well-studied field now, continues to be a source of practical extensiori/homologation technologyThe general reaction is outlined in Scheme 4. The diazoalkane, shown in resonance forms (11a) and (11b), reacts with... 

A diazo ester or alkane will react with a ketone, under Lewis acid catalysis, to give the homologated product. This reaction is most often used for one-carhon ring expansion, as illustrated hy the conversion of (166) to (167 equation 69). The regioselectivity of the (166) to (167) transformation, 98 2 in the example illustrated, was found to depend on both the diazoalkane and the Lewis acid used. With diazomethane and boron trifluoride, a 1 1 mixture of regioisomeric products was observed. 

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