Cyclobutyl chloride, reaction

The 3-ewrfo-(trimethylsilyl)bicyclobutonium ion 431 is also obtained directly from a four-membered-ring progenitor, i.e. 3-(trhnethylsilyl)cyclobutyl chloride 432, by reaction... 

Cyclobutyl chloride does not react with Ph2P- ions in the dark or under photostimulation in liquid ammonia. On the contrary, cyclobutyl bromide (77) reacts with Ph2P ions in the dark (15 min, 42% of substitution product 78) as well as under photostimulation (83% of substitution) (equation 64). p-DNB does not affect the dark reaction while it partially inhibits the light catalysed one. In the latter case, the amount of product obtained is similar to that formed under dark condition151. 

Another valuable alternative to the Hunsdiecker reaction is the Kochi modification,3 which employs a Pb(IV) reagent. It is a one-carbon oxidative degradation of carboxylic acids and is suitable for synthesis of secondary and tertiary chlorides as exemplified by the transformation of carboxylic acid 10 to cyclobutyl chloride (11) mediated by lead tetra-acetate (LTA).16 Further improvement of the Kochi modification employs LTA under milder conditions where N-chlorosuccinimide (NCS) is used as chlorinating agent and a mixture of DMF and HOAc as solvent.17... 

All these fairly similar results are, however, in sharp contrast to solvolysis of cyclopropylmethyl chloride, which is much more reactive than cyclobutyl chloride or 4-chlorobut-2-ene (Roberts and Mazur, 1951 a). There was also positive evidence for internal return in the cyclopropylmethyl chloride solvolysis, although the solvent used (50 aqueous ethanol) is known to be unfavorable for internal return. Another reaction, closely related to the protolysis of cyclopropyldiazomethane mentioned above, is the reaction of that diazoalkane with ethereal benzoic acid. The product ratio cyclopropylmethanol cyclobutanol = 5.8 indicated a strong decrease of skeletal rearrangement (Moss and Shulman, 1968). 

Chloro-4-cyanobutane undergoes a high-yielding intramolecular cyclization under basic solidrliquid two-phase conditions in the presence of tetra-n-butylammo-nium chloride to form cyclobutyl cyanide 1-chloro-4,8-dicyanooctane is formed as a by-product (ca. 10%). No cyclization occurs in the absence of the ammonium salt or when aqueous sodium hydroxide is used [29]. Attempts to produce the cyclobutyl derivative in a one-pot reaction of 1,4-dichlorobutane with sodium cyanide/sodium hydroxide gave only a 9% yield, with 1,4-dicyanobutane (63%) and l-chloro-4-cyanobutane (18%). A similar intramolecular cyclization of (3-chloropropyl-thio)acetonitrile yields 2-cyanotetrahydrothiophene (80%) [30]. 

As shown by their reaction chemistry, cyclobutyl Grignards likewise do not rearrange to either their 3-butenyl or cyclopropyhnethyl isomers reaction of cyclobutyhnagnesium chloride with benzoic acid results in almost quantitative yield of cyclobutane accompanied by only 1% 1-butene. In contrast, the cyclopropyhnethyhnagnesium chloride is ca... 

B. Cyalobutyl toaylate. A 500-mL, three-necked, round-bottomed flask fitted with a stirrer and a thermometer is charged with 200 mL of pyridine (Note 5) and 32.3 g (0.448 mol) of cyclobutanol. The solution is stirred and chilled to 0°C, and then 89.8 g (0.471 mol) of p-toluenesulfonyl chloride (Note 5) is added in portions over a 20-min period. The reaction mixture is allowed to warm to room temperature and is stirred for 16 hr. The mixture is recooled to 0°C, and poured into 260 mL of concentrated hydrochloric acid in 800 mL of ice water. The mixture is extracted with three 300-mL portions of ether and the combined ethereal extracts are dried over anhydrous magnesium sulfate. The drying agent is removed by filtration and the filtrate is concentrated on a rotary evaporator. The residue 1s held under high vacuum (0.03 mm) at room temperature for 3 hr to give 93.3 g (92%) of cyclobutyl tosylate as a pale yellow oil (Note 7). 

Using a somewhat similar reaction sequence cw-l-bromo-2-vinylcyclopropane was reacted with various acid chlorides and transformed stereospecifically to 1-acyl-2-vinylcyclopro-panes. Very good yields were obtained thus, when the bromide was allowed to react successively with tert-butyllithium, phenylsulfanylcopper and cyclobutanecarbonyl chloride at — 78 °C, cyclobutyl d5-2-vinylcyclopropyl ketone (2a) was isolated in 93% yield. 

A wide variety of hydroxylamines, e.g. 7V-phenylhydroxylamine, 0-benzoyl-A-ter/-butylhy-droxylamine, and A-(a-cyanoalkyl)hydroxylamines, added smoothly to cyclopropanone or 1-acetoxycyclopropanol to form the adducts 13, 15 and 17, which were conveniently converted into -lactams 14, 16 and 19 a procedure which resembles the cyclopropylcarbinyl cyclobutyl rearrangement. The former two reagents gave hydroxyamine-type adducts 13 and 15, which rearranged spontaneously into )5-lactams, while with the latter reagent subsequent reaction of the adduct 17 with p-toluenesulfonyl chloride was required to form a species 18 which easily underwent ring enlargement. ... 

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