Spirocyclic derivatives

Phospha(thia)zenes with four coordinate sulfur atoms continue to exhibit interesting chemical and biological properties. The reactions of NPC12(NSOX)2 (X=Ph,Cl,F) with the aliphatic difunctional reagents NH2(CH2)2 3YH (y=NH, O) give the spirocyclic derivatives NP[NH(CH2)2 3Y] (NSOX) 2. The " P nmr chemical shifts of... 

The generality of these observations is supported by the data in Scheme 8. In the case of the reactions of monosubstituted l-(l-alkynyl)cyclopropanols 15, 5-substituted cyclopentenones 17 are obtained with complete selectivity when trans-15 are used as substrates. On the other hand, 4-substituted cyclopentenones 16 are obtained with good to high regioselectivity by employing ferf-butyl-dimethylsilyl ethers of cis-l5 as substrates. Furthermore, 5,5-disubstituted cyclopentenones 20 including a spirocyclic derivative are obtained selectively starting from 2,2-disubstituted l-(l-alkynyl)cyclopropanols 18. 

Bond length and angle variation in geminal and spirocyclic derivatives. 

The 4/f-pyran ring C in spirocyclic derivative 18 is almost planar with maximum deviations about 4 pm and is somewhat distorted by nonbonded interactions due to the bulky 2,6-/er/-butyl groups52 (see Table I). 

The AGe values in the spirocyclic derivatives (Table 39) are smaller than those in regular germocanes. Thus the TBP coordination polyhedra of the Ge atoms in the former are less distorted. The N —> Gc distances in spirocyclic germocanes are also smaller, which indicate a stronger coordination in these compounds. 

Spirocyclic derivatives 118 of pyranoses were prepared in moderate yields by tethering the succinimide on C-6 of the protected monosaccharide skeleton [24c]. The photochemical behavior of 1,6-anhydro sugars 119 [78e], 121 [78f), and 123 [78e] that bear the succinimide moiety in 2-, 3-, and... 

The reaction of N3P3C16 with catechol (8), 2,3-dihydroxynaphthalene (11), 1,8-dihydroxynaphthalene (17), 2,2-dihydroxybiphenyl (11), and several aliphatic diols (21, 399) gives spirocyclic derivatives. A typical example is... 

The reactions of N3P3C16 with ethylenediamine and ethanolamine give spirocyclic derivatives (25) and not ansa-compounds. Aliphatic and alicyclic diols also yield spirocyclic derivatives (26, 31). Inclusion clathrates formed by spirocyclic phosphazenes with aryldioxy substituents (2) have been studied by mass spectrometry, broadline NMR, and X-ray techniques (4). Some conclusions on molecular motion in these compounds have been deduced. 

Ethyl acetoacetate reacts with 2-(A-benzylamino)-5,6-dihydro-6-methylene-4/f-1,3-thiazine (309) in the presence of manganese(IV) acetate to give the spirocyclic derivative (310) (Scheme 62). The starting material for this reaction is obtained from the A-butenylthiourea (311) by iodocyclization and elimination of hydrogen iodide from the intermediate iodomethyl-1,3-thiazine (312) <91TL7111 >. 

Spirocyclic Compounds. Reactions of ring systems containing NPCI2 units with difunctional reagents HX-(CH2) -YH (X,Y == NH, O, NMe n 2—4) lead to spirocyclic derivatives. - If X or Y = NH only mono(spirocyclic) derivatives... 

Reactions with Alcohols.—Reactions of (NPCla)a and (NPCla)4 with NaOPh have now been thoroughly investigated. Substitution reactions of the rings as well as the polymer (NPCla)n with alkyl- and aryloxides are accelerated drastically by addition of (Bu4N)+X- (X = Cl, Br) to the reaction mixtures. Mono-spirocyclic derivatives of (NPCla)a have been prepared from reactions with some dihydroxybinaphthyls the conjugation within the naphthyl moieties in the... 

Isoarsindolines (130) and (131) are prepared by two routes that both involve reaction with o-xylylene dibromide (129) <45JCS30,47JCS662). In the first synthesis, where PhAsNaz reacts with the dibromide, EtOAc is crucial and acts as a reaction promoter (Equation (35)). The low yields of isoarsindolines result from secondary reaction of the product arsine with dibromide (129) to give the spirocyclic derivative (132) after loss of the. 45-substituent. Similar attempts to make the isostibaindoline have failed <45JCS30>. 

Some carbohydrate acetylenic alcohols have been converted to metal carbene spirocyclic derivatives, e.g. 22 (Scheme 4) Acetobromoglucose has been converted into tri-O-acetyl-D-glucal in 90% yield by way of a glycosyl chromium-(III) complex, and an organomercury intermediate featured in a synthesis of tri-O-benzyl-2-C-methyl-D-glucal covered in Chapter 14. 

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