Dimetilol aldehitlerin fenol ve naftollerle reaksiyonu

Abstract

Birimimizde daha önce yapılan çalışmalarda, dimetilal ketonlar ile 2-naftal arasında yapılan reaksiyonlar sonucunda naftopirananaftopiran türevleri sentez edilmiştir. Bu çalışmada ise «<,.<. -dimetilal aldehitlerin 2- naftal ile reaksiyonları incelenmiştir. Bunun için butiraldehitin formaldehitle reaksiyonu sonucunda -c,.<- dimetilal aldehit türevleri hazırlanmış ve daha sonra 2-naftol ile reaksiyona sokulmuştur. Deneyler sonucunda, dinaf toksanten bileşiği ele geçmiştir. Dinaf toksanten bileşiği reaksiyon koşullarında for maldehit ile 2-naftolün reaksiyon ürünüdür. Burdan hareketle -c, ^c -dimetilal bileşiklerinin reaksiyon ortamında bozunarak farmaldehit verip vermediği, bu bileşiklerin hidrazonlarının TLC ile inceleyerek araştırılmış ve formaldehit tespit edilememiştir,

Naphthopyranopyran type compounds uere recently produced by the reaction of -* - -* -dimethylal ketones with 2-naphthal in organic chemistry department. Reac tion of «-c, -^ -dimethylol aldehydes with 2-naphthol under similar condition was studied in order to produce corresponding naphthopyranopyrans. R- CH"DH I 2 C- Cv- CH, I V 3 VD CH2QH + 2 %cbc? CH. ^, <*£ - Dimethylolketone Naphthapyranopyran «- C,-4-DimethyİDİ butyraldehyde and o-d,. CH"0 > Xanthene derivatives (fl, 2 ; 7, aJ-Dibenzoxanthene) However, «<£, *£. -dimethylol aldehyde did not produce any formaldehyde when it was reacted with H"S0, under the similar condition. It was then concluded that «<, «*c -dimethylol aldehyde reacted with 2-naphthol to form intermediate which rearrangement to give dinaphthoxanthene. The purposed reaction mechanisms were as follows : Scheme I, Acid pratones attached one hydroxyl of dimethylol following, one mole of water elimination a carbocations forms then reaets with 2-naphthol to give intermediate (I) which -is basicly in the form of semi-acetal (2). Protonation and water elimination (2) gives carbacation intermediate (3) that rearranges to more sTable carba cation (4). This carbacation (k) acts as an electrophile to reacts with another 2-naphthol molecule and produces the product (5) which is a vinyl ether. This vinyl ether type intermediate product (5) is easily converted by the action of catalyst, to a mixture of dinaphthoxanthene and ~< -manomethylol aldehyde. vm CH20H CH20H Î-C-C ^ + \KJ OH,,+ CH20H CH2DH CHo0H CH OH CH,QH (5) 0-CH=C - R CH"DH I 2 +R-CH-CH0 «c-monamethylol aldehyde [1,2;7,a]öibenzaxanthene Scheme I IX In order to find aut the reaction of aldehydes with 2-naphthol, hutyraldehyde and valeraldehyde mere reacted with 2-naphthol. Corresponding Bis-phenol type products, i.e., 1,1, -Bis (2-Hidroxynaphthyl)butane and 1,1 -Bis ( 2-Hidroxynaphthyl) pentane and were recovered as well as, small amount of acetal type com pounds. R -CHG + GH R - C- H R= -C2H5> -CH. R - C - H Q Bis- phenol type product. D Acetal type product.