A,P-Ethyleneoxo compds

Mercuric chloridejoxalic acidlsilica a,p-Ethyleneoxo compds. from 3-hydroxythioenolethers... 

A soln. of startg. allyl alcohol in ether at 0" treated successively with 1.5 eqs. methyllithium, Me3SiSiMe3, and HMPA, ether removed under N2, and heated at 80 for 24 h - product. Y 75% (Z E 2 1). The allyloxides may also be generated in situ via carbophilic addition to a,P-ethyleneoxo compds. or by addition of vinyllithium to 0x0 compds. a further synthesis of 2-ethylenesilanes from 0x0 compds. is thus available. F.e.s. J.R. Hwu et al., J. Am. Chem. Soc. 110, 7252-4 (1988). 

Spiroketals from a,p-ethyleneoxo compds. Stereospecific heterodiene synthesis... 

Titanium tetra-n-butoxide j cuprous chloride jp-toluic acid a,p-Ethyleneoxo compds. ifrom 2-acetylenealcohols Meyer-Schuster rearrangement... 

O-silyl O-alkyl keteneacetals 43, 869 Aldehydo-a,P-ethyleneoxo compds. 

Acetylenealcohols a,p-Acetyleneoxo compds. Alkylideneketenes Allene oxides Allenyl ethers 2-Ethylenealcohols a,P-Ethyleneoxo compds. 

Acyl-(3 or 5)-hydroxyisoxazolidines from a,P-ethyleneoxo compds. and hydroxamic acids Regiospecific ring closure... 

Methyl-2-butenal added via syringe to a soln. of tris(methylseleno)borane in chloroform at room temp, under argon, and allowed to react for 5 min - 1,1-bis-(methylseleno)-3-methyl-2-butene. Y 70%. This is the first direct transformation of a,P-ethyleneoxo compds. to their selenoacetals. F.e., limitations, and method (with selenols and 0.1 eq. ZnCl,) s. R. Dieden, L. Hevesi, Synthesis 1988, 616-9. 

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