Lactam acetals: Part XXIII. Synthesis of lactam spirocyclic acetals and their use in ω-hydroxyalkylation reactions

Abstract

Lactarn spirocyclic acetals, prepared by trans-acetalisation of lactam 2,2-dimethoxy acetals (1) with diols, have proved to be  useful reagents for 61-hgriroxyalkylations under mild conditions and without the use of acid or base. Thc general applicability of this reaction for C-,N-,0- and S-w-I Hydroxyalkylation reaction has been demonstrated by reacting acetals 5s-i uvh carboxylic acids, thiophenols. 3-formyhndole and dibenzyl phosphate when the correspondmg o-hydroxynlkylnted products were obtained in good yields. This method provides a convenient synthesis for mononcyl diols, arylmercaptoalkanols, N-hydroxyalkylindoles, and phosphate esters, which usually have to be prepared by multistep synthesis and using acid or base catalysis.