Electrophilic Cyclopropyl Heteroatom Substituted conjunctive Reagents

7 Electrophilic Cyclopropyl Heteroatom Substituted Conjunctive Reagents 

Inverting the electronic sense of the small ring conjunctive reagent expands the range of substrates that would be suitable reaction partners. The aldehydes 37 a 88) and 38 89 are available by the formylation of the corresponding lithium salt with DMF. 

Alternatively, 37 a and 37b derive from alkylation of the arylthioacetonitrile followed by reduction of the nitrile directly to the carboxaldehyde (37a in 71 %90) 37b in 

47 % overall88), Eq. 46). The bifunctional aldehyde 42, which exists as its lactol 43, arises by the direct formylation method since the lithium salt 41 is nicely available by direct metallation of the cyclopropane 40 (Eq. 47) 92). Acylation of 1-lithium-cyclopropylphenyl sulfide 30 with methyl benzoate to give 44 has also been recorded (Eq. 48) 92). 

The oxygen derivative 39a has its origins in the acyloin reduction product of diethyl succinate 45. A benzylic acid type of rearrangement of in situ formed 

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