Octahydroxycyclobutane (1) reacts with various monoorganoboranes to give in high yields the tetrakis[organoboranediylbis(oxy)] derivatives 2a -d. These react with tertiary amines to yield either 1 : 2 or 1 : 4 adducts. Depending on the organo substituents at the boron atoms, alcoholyses of 2a -d result in either partial or complete deborylation giving e. g. tetraalkoxybis[phenylboranediylbis(oxy)] derivatives of the cyclobutane ring (7b, c), or, with ring-opening, dimethyl dihydroxyfumarate (5).
Hydratisierte Oxokohlenwasserstoffe, 11)
Herstellung und Reaktionen von Tetrakis[organoborandiylbis(oxy)]cyclobutanen
Aus Octahydroxycyclobutan
(1) erhalt man mit verschiedenen Monoorganoboranen in hohen Ausbeuten die Tetrakis[organoborandiylbis(oxy)]-Derivate 2a -d, die mit tertiaren Aminen 1 : 2sowie 1 : 4-Additionsverbindungen bilden. Bei der Alkoholyse lassen sich 2a -d in Abhangigkeit von den Organo-Substituenten an den Bor-Atomen partiell und vollstandig entborylieren. Man erhalt z. B. Tetraalkoxybis[phenyIborandiylbis(oxy)]-Derivate des Cyclobutan-Rings (7 b, c) oder, infolge Ringoffnung, Dihydroxyfumarsaure-dimethylester (5).
The cyclic polyols triquinol [C(OH),], and leuconic acid [C(OH),], have been known since the previous c e n t ~r y ~, ~) .
A third compound of this class, octahydroxycyclobutane [C(OH)Z]4, was first synthesized nearly two decades ago4). Except for a few reports concerning their structures, ring cleavage5), and some condensation reactions with amines,), the chemistry of these interesting and unique polyketohydrates has generally been neglected. They were, however, quickly recognized as ready precursors for the syntheses of the, as yet elusive, neutral cyclic oxocarbons7).
Utilizing the well known high reactivity of certain organoboron reagents towards hydroxyl groups'), we hoped, through a sequence o f borylationdeoxyborylation, to facilitate the dehydration of these ketohydrates. In this report we describe the reaction of one of these, octahydroxycyclobutane (l), with various organoboron reagents.
Compound 1 was expected to have special properties because of its strained four-membered ring and the sterically rigid hydroxyl groups.