Tables/database/literature of specific or optical rotation

I'm looking for a comprehensive reference of experimental [specific rotation](https://en.wikipedia.org/wiki/Specific_rotation) or [optical rotation](https://en.wikipedia.org/wiki/Optical_rotation) data. It can be a published literature review, a free web database with API access or one that permits scraping, or even a table on a web page with references.


ChemSpider pages link to outside sources (I think only chemical suppliers) for optical rotation, but this is problematic:


* it's unclear what molecules contain this information (not all stereoisomers do),
* not all the product specification pages on the suppliers' websites actually contain the data,
* the values aren't available through the ChemSpider API, and
* it's forbidden to screen scrape ChemSpider pages.


The story seems to be similar for PubChem, though they allow scraping within reason.


For example, [here](http://pubs.acs.org/doi/abs/10.1021/cr990044u) is a review collecting experimental electron affinities for a large number of small molecules and elemental clusters. It's fine that this isn't web-based, because all the values are together and in bulk; writing a PDF scraper is worthwhile because there are so many entries.


Also acceptable would be a book, such as the comprehensive reference from [Huber and Herzberg](https://archive.org/details/MolecularSpectraAndMolecularStructureIV.ConstantsOfDiatomicMoleculesK.P.HuberG.Herzberg) that contains rotational constants, bond lengths, and other constants for diatomic molecules.


