Indan ring

The MS-MS data from metabolite 5 shows a base peak at m/z 437, at an increase of 16 Da over the parent drug, but, in common with Indinavir, ions at m/z 364 and 465. Of most significance is the ion at m/z 465 which indicates that the extra oxygen atom is associated with the indan ring structure. 

There are many similarities between the MS-MS spectra of the (M + H)" " ions of metabolites 2 and 3, with the molecnlar weight of the latter being 16 Da greater than the former. Ions occnr in both spectra at m/z 374 and 273, thns snggesting that this additional oxygen atom has been incorporated into the indan-ring part of the molecnle. 

High molecular weight soluble polymers were not obtained due to cross-linking reactions. These cross-linking reactions involved partial cleavage of the indane ring and multiple acylation reactions [17]. 

The chromane and indane rings in both synthetic brazilin and haematoxylin are considered to be cis fused (ref.115,117). However... 

In particular, the key intermediate product 381 in the synthesis of wighteone was prepared by the oxidative rearrangement of 3 -iodotetraalkoxychalcone 380 [474] and the key step in the synthesis of ( )-indatraline involved the HTIB-promoted diastereoselective ring contraction of a 1,2-dihydronaphthalene 382 to construct the indane ring system 383 (Scheme 3.152) [475]. A similar oxidative rearrangement of 3-cinnamoyl-4-hydroxy-6-methyl-2/7-pyran-2-ones with HTIB in dichloromethane followed by cycliza-tion was used by Prakash and coworkers for the direct conversion of o-hydroxychalcones into isoflavone derivatives [476]. 

On the basis of the possible transition state assembly 123, Ghosh and covrorkers further speculated that the a-chiral center or the indane ring... 

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