Diastereoselective synthesis of vicinal cis-dihydroxyheterospirocycles by one-pot epoxidation/spirocyclization of C(3)-functionalized cyclohex-2-en-1-ols.

Spirolactones, spirotetrahydrofurans, and spiropyrrolidines containing a vicinal cis-diol adjacent to the spiro-carbon center are prepared by one-pot epoxidation/spirocyclization of cyclohex-2-en-1-ols bearing an ester, alcohol, or amide functional side chain at the C(3) position of the ring.

Synthesis of cis-3-acyl-4-alkenylpyrrolidines via gold(I)-catalyzed cycloisomerization reaction of (Z)-8-aryl-5-tosyl-5-azaoct-2-en-7-yn-1-ols.

(Z)-8-Aryl-5-tosyl-5-azaoct-2-en-7-yn-1-ols were cycloisomerized to the corresponding cis-3-acyl-4-alkenylpyrrolidines when treated with a catalytic amount of Ph(3)PAuCl/AgOTf in CH(2)Cl(2). The reaction proceeded via attack of the hydroxyl group onto the gold-activated alkynes followed by [3,3]-sigmatropic rearrangement to generate cis-3-acyl-4-alkenylpyrrolidines in good yields. This transformation can be applied to the synthesis of cis- and trans-3-acyl-4-alkenylcyclopentanes from (Z)- and (E)-8-aryloct-2-en-7-yn-1-ols, respectively.